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160hp or 180hp? That is the question.

I am having trouble deciding which to buy. There are several -4's with 160hp but not so many with 180hp. Is there really a big difference? I have flown one with 180hp but not 160hp or even 150hp. What do you guys think? And what about an IO-360. Does the injected make a big difference?
 
Depends

FP or Constant speed?

a 180hp FP will not be making 180hp anyway..Assuming its pitched for a reasonable cruise.

A 320 with with a CS prop will have more climb performance than a 180HP with a FP cruise prop.

The IO makes no difference to performance, it does make a difference to economy (assuming you run LOP)

Perssonally I'd have a 180hp regardless (either fp or CS)..then again I'm greedy.

Note the only difference will be in the climb..cruise will be barely noticable.

Frank
 
Van designed it around a -150

If you want the handling benefits of a -4 put a 160 in. (Van designed it around a -150) If going fast in a straight line is what you want go for a 180 (or 200). But then why build a -4?

To me its all about weight.
 
If you want the handling benefits of a -4 put a 160 in. (Van designed it around a -150) If going fast in a straight line is what you want go for a 180 (or 200). But then why build a -4?

To me its all about weight.

Happily.................I found ..... It's all about POWER!!!

L.Adamson --- RV6A 180HP/CS
 
HP? MORE!

More is better, that's the short answer to the question. But, keeping a 4 light and in balance is also important.

For me, the 180HP O360 was a good starting point. For exactly ZERO weight increase, I had 9:1 pistons installed, got it flowed, added injection, LSE Plasma II ignition, and of course the cross over exhaust.

Dynoed at 205. I stayed FP with the prop for balance purposes, and it was excellent.
 
180 for me

I have an O-360 and can't imagine why I would want an O-320. In cruise I throttle back and get 200 mph at 8gph. I have a FP prop, so I give up a little in climb. But still, with bags, fuel and two people it will still have an intitial rate of 1800 - 2000 fpm depending on temperature, and still has 1000 fpm at 14000 msl loaded. (I've done that with ice on the plane).

The only thing is, keep it light. Mine weighs 985.
 
Bill, did you consider a light CS prop like the MT? And what kind of numbers do you get with that power and a FP? Also, empty weight? And who did your engine work?

Enough questions?


George
 
Brent - same question for you... MT prop a consideration? And what power setting gives you a 200 mph cruise?

Thanks --


George
 
Assuming money is not a factor I would have IO-360 parallel with one Rose EI and a MT constant speed prop. You could cruise at 10k feet with 40 BTDC timing getting some great fuel mileage and still get out of a 1800' grass strip in August with a passenger.

Just the engine and prop would cost you around $35k though. Most RV-4's are going for under $50k now. Not sure that is a sound financial decision (not that any airplane is) since that engine and prop would get you the same if not better performance in an RV-8.

Build what you want to build though.
 
Why not take a look at putting an IO-340 on your -4? You get some extra HP and no extra weight.
 
Thanks for all the info. I would like to build one but I don't have that kind of time right now. Just had a little girl and I don't think the wife would like it too much (I will wait until we have a boy and he is about 8 yrs old). So for now I am just going to buy one but -4s with 180hp are limited. So I was thinking I would settle for 160hp instead. Or wait for a good -4 with 180hp.
 
I'm with you, Imback - I wish I had the time to build one the way I'd want it, but I simply don't. Next life I'll play for 70 years and then get a job.

You're right, 180 hp RV4's are in short supply on the used market, but a good 160 hp CS bird should be able to be bought for a pretty fair price. I have a Citabria that is a good plane, but the 4 does everything it can do much better, except for the floats. That part I'll miss.

I've been keeping track of the recent 180 hp sales. One on Barnstormers just sold for something probably in the mid 40's, asking price was 48k. I never saw the plane, but the person helping with the sale said the owner was disappointed in the offer. Another one just popped up as an estate sale. Hopefully soon I'll be in a position to buy one instead of watching them pass me by. Obama hasn't filled up my gas tank yet or paid my mortgage...

Good luck in your pursuit!


George
 
Hey George. I have also been watching the -4's with 180hp. The blue and white one listed for 48 sold for 45. I sent an email wanting more info on the estate sale yesterday, but I haven't heard anything yet.
 
Bill, did you consider a light CS prop like the MT? And what kind of numbers do you get with that power and a FP? Also, empty weight? And who did your engine work?

George,

Yeah I did consider a CS prop. I evaluated the MT, but didn't bite on it because (at the time) they just gave up too much speed in cruise. The composite props were all waaaay too pricey at the time, and I just wasn't willing to hang the CS Hartzell on the nose.

With my Amar-Demuth turning 2550 or so, I usually saw 165 knots true in cruise. This was running LOP most of the time, with fuel flows in the low 7's at 11000 - 13000 MSL. There was more speed to be had in this bird - quite alot more - but by the time I sold her I had my head back up in the clouds with another major project underway.

Empty weight was 1025.

Monty Barrett (Barrett Performance Aircraft, Tulsa) did the engine. Later, I added a Lightspeed Plasma II ignition to run LOP. It was a great plane; but was sold back in 2000 to make room for my new 8.

The 4 has a lighter touch; lighter feel to it than the 8. The 8 can be just a little heavy feeling, which I think is due to its higher inertias in pitch/roll. Still nice though.
 
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360 + CS

I have a carburated 360 with a Hartzell CS prop. It's a bit on the heavy side, but, it eliminates the 4s aft CG problem. I can haul around just about anybody I can get in the back seat. Also the Rocket turtledeck helps with the back seater's space. The canopy for the backseater is over 3 inches wider from the shoulders up and 3.5 inches taller....

Just my 2 cents....
 
I just seen another 180 HP on Barnstormers get sold that was listed for $49,900, but not sure what kind of price he got. It was listed on July 22. His ad stated it had the Sam James wingroot fairings for a pickup of 2 to 3 mph, and the Sam James cowling with the fiberglass plenum chamber for a pick up of another 12 mph. He said all of this gave him a 200 mph cruise.

I refreshed my memory with Van?s numbers on his site, which plenty of people seem to state are fair and accurate numbers that they can vouch for. For a 180 HP engine using Van?s standard parts, they too, are showing the 200 mph cruise from the 180 HP engine at gross weight. Is anyone getting some noticeable speed increases from the Sam James cowling and wingtips?

Also looking at Van?s site, there is only a 8 mph difference between the 180 HP and 160 HP engines at gross weight. A 160 HP at gross weight shows a 192 cruise at 75% power.

Has anyone else taken note of 2002 RV-4 on Barnstormers that was listed on July 23, and is priced at $42,000? It?s a 160 HP, with the climb prop. I called Sunday on it and he still had it. The pics look super, and if it looks as good in person, probably the best deal out there on a 4 right now. It only has 325 hours TTSN on airframe and new engine; not overhauled hours. It is in Reno, NV. I came very close to taking the plunge on this one, but kind of have my mind set on building me one for now. Has anyone else looked at this plane, or familiar with it? I?m really surprised he still has it. The cat decals look super too.
 
Hey Wrongway -

I sent you a PM. That one with 35 hours isn't on Barnstormers anymore, unless I missed it.


George

Stan, the man that owned it, wrote me and said he sold it Wednesday to somebody out in NM. I didn’t think it would last much longer. That one looked really nice. There are others listed on Barnstomers for low forties, and nearly all have low hours on the AF, although from the pics, I don’t think that were as near as nice as this one was, and again, it only had 325 hours on a new engine, compared to most others going in the low forties seem to be coming up on nearly 2,000 hours since last overhaul.
 
160 HP will do 200

My buddy Brian, went to 7500' DA a couple of days ago with his -4 and the new Catto two-blade. It turned 2730 RPM and the Dynon showed a TAS of 199 MPH. I asked him if he'd leaned it and he said no, so I figure he left 20 or so RPM and a coupla MPH on the table.

This prop picked up 6 MPh over the Sterba.

Regards,
 
:confused:

I'm looking at 2 planes right now

1- IO-320 300 hrs SMOH Ported/polished Hartzell CS prop

2- 0-360 300hrs on new engine FP prop

2 is a little prettier but also more expensive .

I seem to be gravitating towards the injected CS option . I wonder if the P & P would make it closer to an O-360 power wise.

Any comments ?

I know I'll have a lot of fun with whatever I buy , even 150 hp FP ,but I'm obsessing over the choices right now !

Marc
 
160 vs 180

Here's my two cents worth, I have a RV6A with Lyc 160 0320 c/s. Would not trade it for a 180 hp 0360. Flys side by side with the 180 on 2-3 gallons less per hour. I can maintain 1000+ climb through 10,000 on a cool day. I flew a RV4 for several hundred hours with a 150 hp. Wonderful experience, great airplane! Again, the best advice is listen to your heart and then to your brain, do what seems right.

Jerry Martin
N331RD
 
:confused:

...I seem to be gravitating towards the injected CS option . I wonder if the P & P would make it closer to an O-360 power wise.

Any comments ?
...
Marc,

At OSH I spoke to one engine builder about the P&P and EI. He told me that on an O-320 a light P&P will add around 3 HP per cylinder.

Then when I asked about electronic ignition he said putting on a dual EI set up, it didn't matter which one, you can expect a 6% gain.

That adds up to right around 180 HP without compromising your TBO, according the gentleman I spoke with.
 
Here's my two cents worth, I have a RV6A with Lyc 160 0320 c/s. Would not trade it for a 180 hp 0360. Flys side by side with the 180 on 2-3 gallons less per hour. I can maintain 1000+ climb through 10,000 on a cool day. I flew a RV4 for several hundred hours with a 150 hp. Wonderful experience, great airplane! Again, the best advice is listen to your heart and then to your brain, do what seems right.

A different experience here............... in a way.

I have a 180HP C/S RV6A. A friend has a 160 HP C/S RV9A. As a general rule, I prefer to fly to the destination faster, and do take more fuel as a result. He fly's to conserve fuel. My 6A will climb faster, and outrun the 9A at full throttle.

Last week, the 9A owner flew my 6A on a cross country, while someone else flew his. He flew my 6A with fuel conservation in mind, as he fly's his own plane. And both planes flew together. When they re-fueled, my 6A actually took less than the 9. This goes to show, that a 180 throttled back, can really sip fuel at the rate of the 160..............yet has that full throttle advantage if you want it.

Moral of the story................... use a 180! :D

L.Adamson ---- RV6A
 
no bull

If you really want to know who is faster and by how much. Look up that data for top speeds that was listed on this forum last week. I think the averages are listed too.

Chris M. RV-4 stock 160 hp
 
One other consideration, Mark..

...is how many high altitude airports you plan on flying to. I know that Mel, our resident DAR, has flown out of Leadville, Co. on 150 HP. on a 10,000+ DA day.

That's where the extra horsepower comes in handy, as well as our 100 degree Southern days.

Either airplane will be enjoyable.
 
...is how many high altitude airports you plan on flying to. I know that Mel, our resident DAR, has flown out of Leadville, Co. on 150 HP. on a 10,000+ DA day.
That's where the extra horsepower comes in handy, as well as our 100 degree Southern days.
Either airplane will be enjoyable.

That would be 13,000'+ DA, Warnke wood prop, and the engine had over 2500 hrs on the clock. .
 
Not to change the subject, but...

Who did the overhaul on #1 ? How confident are you in that engine ?
#2 is 300 SNEW factory engine ? That may be more of a factor than performance. In addition, which model Hartzell and what ADs are on it ? Recurring ?

A factory low time engine with FP prop is about as low maintenance an airplane as you can get. Your quality of life will be very high with this combo.
If you feel really confident in the quality of #1, then you might get a bit better OVERALL performance with that combo (cg range, fuel comsumption, etc.).

I doubt you will be disappointed in any case. Good luck with your search and take your time !!! You're likely to have this airplane for many years.

John
 
Thanks to all who have weighed in on my case !

This is also about FP vs CS . I know..... another one of those subjects!

I guess it's pretty standard for people to be comfortable with high TT but MOH engines . I guess there's a certain amount of trust that the overhaul facility did it correctly . The engine in question was done at Ly-Con .

Getting back to the prop . It has the "B" hub so no eddy current inspections but I just clued into the fact that even though the hrs are within overhaul limits , it has exceeded it's calender limitation and I have no idea of the time on the governor . Starting to make a case for the FP route !

This is my first time purchasing a power plane and the whole process has gotten a little obsesive . I can hardly wait for the shopping to be over , to have made a decision , and to start having fun !

Marc
 
By design...

I built my stock RV4 in the early 90s with a 150hp 0320a I rebuilt in my garage. I put 1300 hours on it and flew to the Idaho backcountry every summer I wasn't serving overseas. I never had a problem at higher elevation and outperformed Cessnas and Maules all the time. The RV4 was designed around the 0320, kept light it provides excellent performance, well beyond most factory builts. My buddies with 180s could slightly outclimb and outrun me, but not that much...go with it!

Smokey
HR2
 
Thanks Smokey ! When you say go with it , which "it " do you mean ?:)

I'm again starting to think the 160 hp CS at a cheaper price might be more bang for the buck ! Do you think 1018 lbs is an OK weight for a 4 ?

Marc
 
That's a good weight, Marc....

...and another point. If you're planning any formation work, the CS prop sure is a big help in slowing down while in tight quarters.

Regards,
 
C/S or not C/S, that is the question...

Marc,

My RV4 had (and still has) a FP prop. I have flown alot of formation with no worries. Pierre is right, C/S is nice, but not so much for formation but for slowing down and cruise efficiency. Cost wise, a 0-320 with a lightweight wood prop flies great. C/S is worth the extra $$$ in my opinion but not a deal breaker. Having looked and still look at many 4's for customers, the 0-320 C/S combo is rare, most go with a FP 320 or a C/S 180. If it helps, Van flies a 160/wood prop RV4 to work every day in OR.
Questions?

Smokey
HR2
 
Thanks for all the great info guys. I never thought I would get so much feed back. I am also leaning towards the 160hp. There aren't very many 180 hp to choose from and the one that are, are much more expensive. The guy I share the hanger with has a buddy that just came in and he has a very nice -4. He's an F-18 pilot and will be visiting for about 10 days. His -4 is 160hp with fp. I have only flown cessna's so any -4 should be just fine for me. Its funny, the guy visiting knows several rv guys here at my field. Any of you guys around Aerocountry in McKinney Texas?
 
HP?

I enjoy reading these posts, each of us have a different idea of what our mission would be, the diversity that is allowed with these airplanes seems huge but suttle. I remember my first build and thinking a lot along these lines, but years later it all has changed, I would not do some of the things I did and will do lots different, the perspective comes from experence. I have enjoyed flying several differnent enging prop combonations which allows me to find what I care for the most. I am not an aerobatic pilot, I like the transmission and the bigger the "UP" button the better, you can always pull the throttle back. Light, Straight and "KISS"

Any which way you get the plane, you will love it and want to change it. Hope to see all ya's at LOE.

Randy
 
What would Van do (WWVD)?

FWIW, several years ago I was agonizing over what combo to go with for engine and prop. I ran into the man himself (Van) and asked him the same question, specifically for an RV-4. He said the best combo (in his opinion) is a 160 HP O-320 with a constant speed prop.

That being said, I ended up bolting a 180 HP O-360 with a Sensenich on the front end because I came across real good deals on both. Funny how things work out! I do hope to switch to a C/S prop some day.

Rick
 
Yeah, if I had a 0-360 dropped in my lap at a good price, I'd probably go that route as well. I think with the 0-320, one wouldn't be lugging around an extra 20 lbs though, if I remember correctly. And as others have pointed out, it’s quite easy to do a port and polish, electronic ignition on the 0-320 that will probably put you at or over the 180 HP while still having the advantage of the lighter 0-320. Then you've got fuel injection to consider. This will be putting you at or around the VNE of 215 mph at WOT in level flight, I believe, so not sure what I'd do with all of that extra HP.
 
Well Guys.... I think I'm going with the 160 hp P and P'd IO-320 CS set-up . Wow , I can't believe I've actually made a decision !

It's actually the plane that Randy (SportAvServ) built 16 yrs ago . Thanks Randy !

Just working out some details with the owner .

Marc
 
Oops, I think the VNE of the 4 is 210 mph, not the 215 I listed previously. In the pre-plans, Van's is supposed to have flutter tested 10% over that speed.
 
weight differences for various 320 and 360 combinations

Russell from Mattituck engines sent me this, and think others might be interested in what differences there is in weight along with dimensions for their engines. He says they have this on listed on their site some where as well in their Q&A.

"What are the approximate weights and dimensions of the TMX experimental engines?"

For Mattituck engines
Approximate TMX Engine Series Weights And Dimensions (H x W x L):
TMX O-360 Fixed Pitch (Solid Shaft 180HP):
25"x 33"x 29" 286 Lbs.

TMX O-320 Fixed Pitch (150/160 HP) :
22"x 32.2"x 29" 273 Lbs.

13 lbs difference


For fuel injection engines:
TMX IO-360 Fixed Pitch (Solid Shaft 180HP):
24"x 33"x 29" 289 Lbs.( plus 2 LBS for Forward Facing Sump)

TMX IO-320 Fixed Pitch (150/160 HP) :
24"x 32.2"x 29" 276 Lbs. (plus 2LBS for Forward Facing Sump)

13 lbs difference


TMX O-360 Constant Speed (180 HP) :
25"x 33"x 29" 281 Lbs.

TMX O-320 Constant Speed (150/160 HP) :
22"x 32.2"x 29" 274 Lbs.

7 lbs difference

For FI and CS prop:
TMX IO-360 Constant Speed (180 HP) :
24"x 34"x 29" 284 Lbs. (plus 2 LBS for Forward Facing Sump)

TMX IO-320 Constant Speed (150/160 HP) :
24"x 32.2"x 29" 277 Lbs. (plus 2LBS for Forward Facing Sump)

7 lbs difference
 
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